巧算(3x^2+9x+7)/(x+1)-(2x^2-4x-3)/(x-1)-(x^2+x+1)/(x^2-1)
|X-1|+|X-2|+|X-3|+|X-4|+|X-5|+|X-6|+|X-7|+|X-8|+|X-9|+|X-10|
x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
x-1)(X-2)(x-3)...(x-50)+x(x-2)(X-3)...(X-50)+...+x(x-1)(x-2)
y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1
设函数f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10),
(1) x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8
X+7/X+1+X+8/X+2-X+9/X+3-X+10/X+4 的解法
1+x+x^2+x^3+.+x^99+x^100
x(2-1/x)+x/(x^2-2x)÷(3-x)/(x^2-4)
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
(x+2/x^2-x-6)-(2x/x^2-3x)-(x+1/x^2-6x+9)